the one bugger is sometimes a tank is "full" and it takes 6 gallons and sometimes it takes more, I think the fuel fillers here are intended for tanks with bleed valves, so i think full is sometimes a bit less than full. which makes things exciting, being +/- a gallon or so.

This tank, i took 6 gal, which made me think the mpg would be better, but after 75miles i'm getting close to the the empty mark, so I don't know how many miles this tank will go, hoping to get to 100 again before filling.

I think it's time to order a vaporizer maintenance kit, and get a replacement throttle stop screw, it's still leaning out on the highway. It's been a pain trying to get it to run richer.

I get around 25mpg with a worked A14 (1510cc 12.5:1 comp, huge cam and 45mm carbs) with an OD 5 speed and 4.1 gears with very short 215/50-13s. This is on 95 octane, and all city driving, giving it hell most of the time.

If stoplights in CA are 700 feet apart, they're about 200 feet apart here!

3 weeks ago fitted reco A15 engine in my ute. Ground cam, lightened and balanced flywheel, comodore valve springs, dd webber, extractors, two inch exhaust, goes very well.
This week i tested fuel economy, 157kms town and highway, used 13.7L unleaded that equals 32.66MPG or 11.45KPL, im pretty happy with that i think, as i dont nurse it too much

mmm 100miles = 160km around town... not too bad compared to a rich running petrol a15 with su's getting about 220km from 35lt petrol

My best is about 19.02km/l or 55mpg cruisin at 100km/h, i average about 49mpg or 17.2km/l at 115-118km/h (true speed not indicated) running on 98RON with A12, 5 speed O/D and 3.7 H165, 185/60R13 tyres, in a 1200 ute.

my only regret is not getting a bigger tank.

I cut out the spare tire area above the gas tank and built a nice frame bolted between the rails, so upgrading is fairly easy.


Mine is 30 lt or something like that, and in town 100 miles between gas is a bit too often.

I'm tempted to switch to a propane injection system, that will help the mileage a little.

propane power needs a turbo to work best.

The higher octane is nice! Pass everyone on long grades when their ignition starts retarding. High altitude seemed to be less of a problem with propane too.

b210sleeper you inspired me about 12 months ago to do some heavy research into lpg and the datsun and it is going to happen within the next 4 weeks due to my petrol and needle issues with my su's and the inavilability of reasonable priced parts.

Im going twin su lpg set up and just strugling to find a tank that will fir the b110 sedan between the rear wheel arches. approx 800mm

This would give me a lpg tank of 36lt useable gas, might be able to fit a 47lt tank with a bit of massaging for the required crlerance by law.

36lt tank would give me a rang of approx 200kms, 46lt approx 300 to 350km. Way better than my efforts on petrol.

it takes approx 1.2 to 1.4 times the ammount of lpg to the quivelent of petrol to make the same power/ fuel economy compared to petrol. eg 1 lt of petrol burnt would be 1.2 to 1.4 lt gas.

Im planning on setting it all up then skimming the head later on for more compression to take advantage of 110 to 114 octane equivelent here in aus for lpg.

Driving 65 is too hard, i get up over 80 on the freeway here just to keep up.

I'm using new everything.

Datsun made many A15's for forklifts that run propane, so that's not even an issue.

LPG also doesn't wash the oil off the cylinder bores or get the oil dirty nearly as fast.

There was, is and will be many debates around the unleaded vs leaded issue. Many people say that they haven't really seen a detrimental effect on older engines, even ones with cast iron seats. I can only say that I see a lot of old cars fill up with unleaded, and not many that has issues.

But back to your question, only right at the inception of the A series engines, I think they used some kind of bronze compound seat(some of the older members might be able to enlighten us with some more info here), from there on they started using steel. So unless you have a very, very old one, you don't have to worry, it'll be fine with unleaded. And no, if you would have had problems, it would have been because it was designed for leaded, and not unleaded.

The reason you might experience problems, is that the lead, other than lift the octane rating, creates a softer landing when the valves close on the seats, and for the rings on their lands. This stops the lot from wearing away at a fast rate, should they be made from softer compounds. In theory at least that is.

Anyway, if you run it with LPG, there is no cushioning effect whatsoever. Which is also why I doubt that running your older car with unleaded would have to much of an effect on it's lifespan...

If you run unleaded do you have to get the seats changed in the head, Or will they take unleaded due to the fact they were designed for leaded...??